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Environmental process | Environmental review | Contaminated Materials

Contaminated Materials process


The purpose of this guidance is to describe the contaminated materials process for early identification and documentation of known or suspected contamination (including contaminated soil, groundwater, soil vapor, buried solid waste, etc.) in existing and proposed right of way and adjacent properties.

Early identification of contaminated properties allows MnDOT time to:

  • Determine the presence of contaminated materials within the project area so the state can obtain liability protections (if available) and regulatory approvals (if applicable), provide data for the contractor to obtain permits, and include special provision language for the proper management of contaminated materials
  • Conduct investigations to identify the presence of contaminated materials within the project area
  • Evaluate the investigation findings to determine the level of liability, and impact on project costs and schedule
  • Determine if the contamination presents an acceptable level of liability and cost risk that would allow the state to acquire the property and move the project forward, or an unacceptable liability and cost risk that would halt the project and necessitate redesign
  • Develop strategic design changes that protect the State’s long-term liability

Early identification also allows the state to protect construction workers and prevent construction delays and increased costs that result from the discovery of unexpected contaminated materials in the field. Because of the legal complexity and potentially high costs associated with acquiring any ownership interest and undertaking construction in a contaminated property, you should reduce the disturbance of such properties as much as possible.

Threshold criteria

A project with any of the following four threshold criteria may require a detailed Phase I Environmental Site Assessment (ESA) and possibly a Phase II Drilling Investigation to identify the possible presence of contaminated materials.

1. Acquisition of new right of way that will become part of the state’s Trunk Highway system (in accordance with MnDOT Policy OP009 “Environmental Due Diligence for Property Acquisition”)

Acquisition includes, but is not limited to, fee, all forms of easements, and all forms of orders (a complete list of acquisition types is available on the policy webpage). An owner of a property that is the source of contaminant releases (such as petroleum, solvents, metals, polynuclear aromatics, or solid or other hazardous waste) can be named the responsible party for the site and be held liable for cleanup under state and federal law, even if that owner did not cause the contamination.  Under certain conditions, state law (Minnesota Statutes, section 115C.021, subdivision 3a) protects MnDOT from being liable for cleanup of a petroleum release from an underground tank on acquired right of way. Apart from this law, MnDOT has no protection unless it applies for and receives limited liability protection under Minnesota’s Environmental Response and Liability Act (Minnesota Statutes, section 115B) Voluntary Investigation and Cleanup (VIC) program. These liability protections are limited, the regulatory process is complicated, and the cost to obtain and maintain liability protection in perpetuity is substantial. In other words, even when programs apply, legally becoming a responsible party for a contaminated property is always a risk. Furthermore, if the state is acquiring property adjacent to a potential or known Superfund site and inadvertently disturbing or incorrectly managing contamination originating from that site, the state can become the responsible party for the Superfund site, even though it has no ownership interest.

2. Grading and excavation

Projects with grading and excavation can encounter contaminated soil and groundwater. Examples of project work that includes excavation are new roadway alignments, stormwater ponds, utility removals and replacements, culvert replacements, turn lanes, and shoulder or ditch work. Encountering contamination during utility work in developed areas is especially likely. Additionally, the state often encounters abandoned underground tanks during sidewalk replacement, Americans with Disabilities Act (ADA), and urban reconstruction projects. Solid waste and demolition debris are also often encountered during excavation of new storm water ponds.

3. Commercial and industrial locations

Projects in current and former commercial and industrial areas also have a higher chance of encountering contaminated soil and groundwater. Commercial and industrial areas have often used potentially hazardous materials, and have historically suspect waste management practices. These practices could have included on-site burial, illicit disposal of waste materials, and periodic demolition of infrastructure.

4. Groundwater dewatering (temporary or permanent)

Projects with potential dewatering may encounter contaminated groundwater. Shallow groundwater in developed areas has a higher potential for being contaminated. Early identification of dewatering needs allows time to identify and characterize the risk. If contamination is identified, develop a dewatering plan. The plan may include obtaining necessary discharge permits and proper handling of the contaminated groundwater during construction.

Contacting the Contaminated Materials Management Team (CMMT)

Contact the CMMT as early as possible, preferably during the scoping and during the ENM processes. The CMMT work packages can take a minimum of 12 to 18 months to complete prior to project letting. Complexity varies according to project size and how many threshold criteria the project meets.


Early Notification Memo (ENM)

All projects require an ENM. District ENM document writers should follow the threshold criteria outlined in the section above and in the OneENM document to determine when a contaminated materials review is required. Some project work types are exempt from CMMT review. These exceptions are listed in the OneENM document.

Evaluation process

After reviewing the ENM, CMMT will provide an ENM response email with recommended next steps. If the risk of encountering contaminated materials is determined to be low, the response will state that no further CMMT review is needed. In these instances, MnDOT Standard Specification 1717 Air, Land, and Water Pollution will apply. This spec discusses management of unexpected contaminated materials discovered during construction.

If there is a risk of encountering contaminated materials or acquiring potentially contaminated properties, CMMT staff will contact the project manager to discuss next steps in the review process. Below is a high-level description of the right of way review and contaminated materials investigation processes.

EDD processes

All projects that include any type of right of way acquisition require an EDD review per the EDD for Property Acquisition Policy (OP009). CMMT must perform an EDD evaluation each time MnDOT acquires property.

The EDD evaluation is a risk management tool that guides decisions regarding MnDOT acquisition of properties through consideration of the project needs and the short- and long-term environmental risks associated with historical chemical use or disposal of solid waste at the project.

CMMT must complete the EDD evaluation prior to an offer to the landowner for the property acquisition.

There are three EDD levels, EDD-1, EDD-2, and EDD-3. The documentation required to complete each level of EDD is contained in the MnDOT Right of Way Electronic Acquisition Land Management System (REALMS) database maintained by the Office of Land Management (OLM).

The three levels of the EDD evaluation require progressively more information regarding the parcels under consideration for acquisition. CMMT may give clearance to acquire a property at EDD-1 or EDD-2 levels based on the information obtained during the property evaluation. An EDD-3 level evaluation requires MnDOT’s Deputy Commissioner/Chief Engineer to approve (or disapprove) the acquisition. Information regarding the internal procedures for the EDD evaluation is in the Right of Way Manual. A brief description of the three EDD levels follows below.

  • An EDD-1 evaluation: District Right of Way (ROW) provides the general project area information, including the end-points of the project
    • CMMT reviews the project area for identification of potential contamination
    • CMMT determines whether that additional investigation in not needed or, more commonly, additional evaluation is necessary under EDD-2
  • An EDD-2 evaluation: District Right of Way/Land Management provides additional specific parcel information, so that known or suspected occurrences of contamination tie to specific parcels
    • CMMT will conduct a Phase I or Phase II investigation as necessary
    • CMMT must clear parcels prior to acquisition or determine that an EDD-3 evaluation is required
  • An EDD-3 evaluation: District Right of Way/Land Management or project manager provides information on potential high-risk property acquisitions
    • The EDD-3 summarizes benefits and risks of acquiring the property, all feasible and practicable risk mitigation options (such as project design changes to avoid or limit use of the property), and liability protections available from regulatory agencies
    • MnDOT’s Deputy Commissioner/Chief Engineer must review and approve (or disapprove) the acquisition

Most projects only require an EDD-1 or EDD-2 evaluation. Only projects involving high-risk property acquisitions must require an EDD-3 evaluation. Additional information can be found in the EDD Policy and the Office of Land Management’s Right of Way Manual.

Phase I ESA projects

Projects with a potential for encountering contaminated materials require a Phase I ESA. A Phase I ESA is an industry standard, and the requirements of the investigation are outlined by federal regulations and an ASTM standard. A Phase I ESA includes a detailed review of historic land use records, regulatory history, and current land use. The purpose of the review is to determine if current or former human activities on or near a property could have contaminated the soil and groundwater on the property. Depending on the complexity of the project, a Phase I ESA can take from four to eight months to complete. A required component of the Phase I ESA includes a corridor site visit that is completed on a seasonal calendar when the ground is free of snow cover and during the growing season. CMMT staff will retain a consultant, funded from district budgets, to complete a Phase I ESA.

Phase II drilling investigation projects

If the Phase I ESA finds known or suspected contamination on or near proposed or existing right of way or proposed excavation areas, the project will likely need a Phase II drilling investigation (sometimes referred to as a “Phase II”). The purpose of the investigation is to document and characterize contamination within and adjacent to the project area. A Phase II ESA includes field collection and laboratory analysis of soil, groundwater, vapor, and/or waste samples for the presence of chemicals of concern and is generally completed when the ground is not frozen.  Depending on the complexity of the project, a Phase II ESA can take three to six months to complete. Results of the Phase II are used to determine liability associated with property acquisitions and the likelihood of encountering contamination during construction. CMMT staff will retain a consultant, funded from district budgets, to complete a Phase II, funded from district budgets.  CMMT staff will also obtain liability protections (No Association Determination, (NAD)) from the applicable regulatory agency (Minnesota Pollution Control Agency (MPCA) or Minnesota Department of Agriculture (MDA)), and draft construction special provisions as needed.

If liability protections are needed, the CMMT Project Manager will enroll the state project in the applicable regulatory program (e.g., MPCA Brownfields Program). The regulatory agency will then require additional approvals, communications, documentation, and project close-out reporting to ensure that contamination is managed according to applicable regulations. This process can add an additional two to four months to project schedules.

Organizations involved

The MPCA oversees all state contaminated materials investigations, management and cleanup standards, and oversees all state and most federal cleanup projects. They issue all permits and approvals for contamination-related projects (except for those under the jurisdiction of the MDA). The MPCA can grant limited liability protection for acquisition of and work in some types of contaminated properties.

The MDA oversees all state and most federal cleanup projects involving pesticide and fertilizer contamination (all other types of contamination fall under the jurisdiction of the MPCA). They issue all permits and approvals related to this work. The MDA can grant limited liability protection for acquisition of and work in some types of contaminated properties.

The Minnesota Department of Health (MDH) regulates and permits well installation and sealing. They also regulate asbestos abatement.

Metropolitan Council, Environmental Services (MCES) issues permits for the discharge of contaminated water to the sanitary sewer system in the Minneapolis-Saint Paul metropolitan area.